<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			body{
				margin: 0;
			}
			.box{
				width: 333px;
				height: 200px;
				background: #fc3;
				/* position: relative; */
			}
			.inner{
				width: 200px;
				height: 100px;
				background: #f01;
				position: absolute;
				top: 100px;
				left:133px;
			}
		</style>
	</head>
	<body>
		<!-- 
			一个绝对定位的子元素，如果它的父级元素有定位，子元素就针对父级元素进行定位，就不再针对文档
		-->
		<div class="box">
			<div class="inner"></div>
		</div>
	</body>
</html>
